China yesterday became the third state on the planet - after the former Soviet Union and the US - to launch a manned spacecraft. Such a successful introduction of advanced technology by a developing country might be thought a cause for international celebration - but that is not how the militarists in Washington will see it. There, it is likely that the launch will be used as further evidence of a "China threat", while China's own proposal - for a treaty banning weapons from space - will be rejected.

The danger is that President Bush will repeat the US reaction to the Soviet space programme. In the 1950s, when Moscow launched Sputnik, the first satellite, it triggered a massive military build-up by Washington. It is now US national strategy to prevent any power from rivalling the US in the way that the Soviet Union once did. US strategists see China's huge population and growing economy as providing the state with the potential to challenge America.

The now infamous Project for the New American Century (Pnac) states that for the US the "focus of strategic competition" has shifted from Europe to east Asia. In a discussion of potential strategic competitors to the US, President Bush's national security strategy explains some of the political rational for fearing China: "... a quarter century after beginning the process of shedding the worst features of the Communist legacy, China's leaders have not yet made the next series of fundamental choices about the character of their state. In pursuing advanced military capabilities that can threaten its neighbours in the Asia-Pacific region, China is following an outdated path."

The reality of Chinese power is very different to that put forward by the Washington threat-creation industry. Take the idea of an attack from the mainland on Taiwan. According to the International Institute for Strategic Studies, Beijing has just 60 ships in its navy - only twice the number of tiny Taiwan and a fraction of US strength.

China's real priority is to have enough power to prevent a return to the humiliations of the colonial era. It is too easy to forget that in the mid-19th century Britain used gunboats to force China to import opium, and then took control of China's overseas trade. Other foreign powers joined in and the US kept a fleet operating in China's rivers up until the second world war, when they were forced out by the Japanese invasion.

Today, the US has thousands of nuclear weapons and other missiles able to attack China, while Beijing has little to fire back with. Washington is determined to keep it that way. One of the Pnac members explained that: "The US has never accepted a deterrent relationship with China, the way we did with Russia." To the US military, any space programme it does not control is a challenge to its formal policy of dominating space militarily.

The likely reply from the Pentagon to the Chinese space programme is an intensification of the "son of star wars" project, part of which is being built at Fylingdales in Yorkshire. These missile defences would be able to neutralise a Chinese deterrent, but are better suited to shooting down satellites (including manned spacecraft) than incoming missiles - because satellites follow a predictable path across the sky. It is vital that the British government is cross-examined over the potential anti-satellite role of the Fylingdales base.

In contrast to the US quest to dominate, the Chinese have been campaigning for a UN treaty banning weapons from space. The Chinese draft treaty should be welcomed. There are few new technical problems in creating a verifiable inspection regime for a ban on weapons in space. Right now, there are no weapons above our heads. It is not necessary to put Hans Blix in a space suit to carry out inspections. There are only a handful of space-launch and missile-defence sites around the world. Satellites and other space vehicles are tiny, so it is easy to check if a ray gun is hidden inside.

US behaviour over arms talks gives ample evidence to those dubious of its peaceful intent. Even President Clinton vetoed UN talks on a space weapons ban. In the absence of any sensible policy from Washington, the UK and Europe must engage in direct talks with the Chinese. We cannot afford to sit back and watch the growing confrontation between the US and China. Britain has a prime minister who tells us he is seriously concerned about the problem of weapons of mass destruction. After the Iraq debacle he can restore his credibility in this area by helping prevent an arms race in space. If the US will not cooperate for now, then we should act with the EU and Russia, pressuring the US to abandon its militarist excesses.

· Dan Plesch is senior research fellow at the Royal United Services Institute